Spectroscopic and in silico study of binding mechanism of cynidine‐3‐O‐glucoside with human serum albumin and glycated human serum albumin

The drug–serum albumin interaction plays a dominant role in drug efficacy and disposition. The glycation of serum albumin that occurs during diabetes may affect its drug‐binding properties in vivo. In order to evaluate the interactivity characteristics of cyanidin‐3‐O‐glucoside (C3G) with human serum albumin (HSA) and glycated human serum albumin (gHSA), this study was undertaken using multiple spectroscopic techniques and molecular modeling analysis. Time‐resolved fluorescence and the thermodynamic parameters indicated that the quenching mechanism was static quenching, and hydrogen bonding and Van der Waals force were the main forces. The protein fluorescence could be quenched by C3G, whereas the polarity of the fluorophore was not obviously changed. C3G significantly altered the secondary structure of the proteins. Furthermore, the interaction force that existed in the HSA–C3G system was greater than that in the gHSA–C3G system. Fluorescence excitation emission matrix spectra, red edge excitation shift, Fourier transform infrared spectroscopy and circular dichroism spectra provided further evidence that glycation could inhibit the binding between C3G and proteins. In addition, molecular modeling analysis supported the experimental results. The results provided more details for the application of C3G in the treatment of diabetes.     

Biosynthesis of cyanidin in cell cultures of Haplopappus gracilis

-Dihydroquercetin proved to be a good precursor for light-stimulated cyanidin biosynthesis in cell suspension cultures of Haplopappus gracilis. Wit     

Acylated cyanidin 3-sambubioside-5-glucosides from the purple-violet flowers of Matthiola longipetala subsp. bicornis (Sm) P. W. Ball. (Brassicaceae)

A novel acylated cyanidin 3-sambubioside-5-glucoside was isolated from the purple-violet flowers of Matthiola longipetala subsp. bicornis (Sm) P. W. Ball. (family: Brassicaceae), and determined to be cyanidin 3-O-[2-O-(2-O-(trans-feruloyl)-β-xylopyranosyl)-6-O-(trans-feruloyl)-β-glucopyranoside]-5-O-[6-O-(malonyl)-β-glucopyranoside] by chemical and spectroscopic methods. In addition, two known acylated cyanidin 3-sambubioside-5-glucosides, cyanidin 3-O-[2-O-(2-O-(trans-sinapoyl)-β-xylopyranosyl)-6-O-(trans-feruloyl)-β-glucopyranoside]-5-O-[6-O-(malonyl)-β-glucopyranoside] and cyanidin 3-O-[2-O-(β-xylopyranosyl)-6-O-(trans-feruloyl)-β-glucopyranoside]-5-O-[6-O-(malonyl)-β-glucopyranoside] were identified in the flowers.     

Anthocyanin inheritance in petals of flax, Linum usitatissimum

Twelve anthocyanins have been isolated from flax: the 3-glucosylrutinosides of pelargonidin, cyanidin and delphinidin; the 3-triglucosides of delphinid     

Seed Polyphenolic Profile,Antioxidative Activity,and Fatty Acids Composition of Wild and Cultivated Carthamus Species

Total flavonoid content (TFC) and cyanidin‐3‐glucoside (Cyd‐3‐glu) of seed and seed coat extract of 16 genotypes from five species of Carthamus were studied, and their major polyphenolic compounds and antioxidant activity of the seed coat extracts were determined using HPLC analysis and DPPH assay, respectively. Additionally, fatty acids composition of the seed oil was analyzed by GC. In general, TFC and Cyd‐3‐glu content of seed coat extracts were higher than those of seed extracts. A novel breeding line with black seed coat (named A82) depicted lower TFC (3.79 mg QUE/g DW) but higher Cyd‐3‐glu (24.64 mg/g DW) compared to the white and other seed‐pigmented genotypes. DPPH radical scavenging activity showed a strong association with Cyd‐3‐glu content (r = 0.84), but no correlation with TFC (r = ?0.32). HPLC analysis of seed coat extracts revealed that four compounds were dominant constituents including rutin (7.23 – 117.95 mg/100 g DW), apigenin (4.37 – 64.88 mg/100 g DW), quercetin (3.09 – 14.10 mg/100 g DW), and ferulic acid (4.49 – 30.41 mg/100 g DW). Interestingly, the genotype A82 with an appropriate polyunsaturated/saturated fatty acids index (5.46%) and a moderate linoleic fatty acid content (64.70%) had higher nutritional and pharmaceutical value than all the other genotypes.     

Genetical and biochemical evidence that the hydroxylation pattern of the anthocyanin B-ring in Silene dioica is determined at the p-coumaroyl-coenzyme a stage

In petals of Silene dioica, gene P controls the 3′-hydroxylation of the anthocyanin B-ring and the hydroxylation pattern of the hydroxycinnamoyl acyl group bound to the 4″'-hydroxyl group of rhamnose of anthocyanidin 3-rhamnosyl(1→6)glucoside-5-glucoside. In this paper, experiments are presented which show that gene P is involved in the hydroxylation of p-coumaroyl-CoA to caffeoyl-CoA, which is then used both as a precursor in anthocyanin biosynthesis and as a substrate for the final acylation.     

Axillary shoot proliferation of blue honeysuckle

Callus cultures of Ajuga reptans flowers produced a complex mixture of cyanidin- and delphinidin-based pigments, of which more than 90% were acylated. The anthocyanin composition varied little during one growth period. During a time span of 5 years no new anthocyanin classes appeared. Quantitative differences in anthocyanin composition between the callus lines and during a 5 year time span were more pronounced. In general, the accumulation of delphinidin-based anthocyanins decreased. The percentage of acylated anthocyanins was stable in time. The accumulation of metabolically evolved anthocyanins (5′-substituted and acylated) decreased during passage from solid culture to liquid culture. The accumulation of acylated anthocyanins was influenced by the type of aeration in liquid cultures. This revised version was published online in June 2006 with corrections to the Cover Date.     

Acylated anthocyanins from the violet-blue flowers of Orychophragonus violaceus

Three acylated cyanidin 3-sambubioside-5-glucosides (1-3) were isolated from the violet-blue flowers of Orychophragonus violaceus, and their structures were determined by chemical and spectroscopic methods. Two of those acylated anthocyanins (1 and 3) were cyanidin 3-O-[2-O-(2-O-(4-O-(6-O-(4-O-(beta-D-glucopyranosyl)-trans-caffeoyl)-beta-D-glucopyranosyl)-trans-caffeoyl)-beta-D-xylopyranosyl)-6-O-(4-O-(beta-D-glucopyranosyl)-trans-acyl)-beta-D-glucopyranoside]-5-O-(6-O-malonyl-beta-D-glucopyranoside)s, in which the acyl groups were p-coumaric acid for 1, and sinapic acid for 3, respectively. The last anthocyanin 2 was cyanidin 3-O-[2-O-(2-O-(4-O-(6-O-(4-O-(beta-D-glucopyranosyl)-trans-caffeoyl)-beta-D-glucopyranosyl)-trans-caffeoyl)-beta-D-xylopyranosyl)-6-O-(4-O-(beta-D-glucopyranosyl)-trans-feruloyl)-beta-D-glucopyranoside]-5-O-beta-D-glucopyranoside. In these flowers, the anthocyanins 2 and 3 were present as dominant pigments, and 1 was obtained in rather small amounts.     

A Thermophilic Acidophilic Bacterium from Hot Springs

A thermophilic acidophilic bacterium was isolated from Owaku-dani hot springs of Izu-Hakone National Park in Japan. This bacterium grows optimally at a temperature of 70°C and a pH of 2~3. The isolate was generally spherical in shape, with a diameter of about 0.8~1.2 μm, being gram-negative and nonmotile. The DNA base composition was 44% guanine plus cytosine. Chromatographic, chemical and infrared spectroscopic analysis of the total cellular lipid showed that the lipid constituents contained mainly ether linkages; long chain fatty acids and derivatives were absent. The data presented suggests that the thermophilic acidophilic isolate may have some relationship to the Sulfolobus.     

Microbial Oxidation of sec-Alcohols to Ketones

The major anthocyanin compound in buckwheat sprouts was determined to be cyanidin 3-O-rutinoside (C3R), based on HPLC data and MS/MS spectra. Investigation of the content of phenolic compounds in commercial buckwheat sprouts indicated that hypocotyls are abundant in C3R and rutin, whereas all of the detected flavonoids are abundant in cotyledons. The superoxide anion radical-scavenging activities (SOD-like activities) of phenolic compounds in buckwheat sprouts and their contents indicated that rutin, isoorientin, and orientin contributed mainly to the SOD-like activity of the extract from buckwheat sprouts. In contrast, the contribution of C3R was substantially lower than that of flavonoids.